Recently, due to rapid popularization of networks represented by the Internet and its technology developments, the user has become able to browse information in the network using not only PCs (Personal Computers) such as a desktop PCs and laptop PCs, but also various information terminals such as mobile phones, PDAs (Personal Digital Assistances), consumer electronics, and car navigation devices. The information browsing software (Hereinafter, “browser”.) is installed in these information terminals. The browser parses a document described in a markup language, for example, HTML (Hyper Text Markup Language), and then, performs a layout making processing based on the parsed result. Thereby, the information on the network (e.g., page) is displayed (i.e., rendered) on the display of the terminal.
First, the terms used in this application are defined.
Network:                The “network” includes various kinds of communications network including a carrier telecommunications network, an intranet, and the Internet.        
Content:                The “content” is a set of information that the user views, including video, image, music or text, or their combinations, which is transmitted via a network or stored in a terminal.        
Web Content:                The “web content” is a form of the content, and a set of information transmitted via a network.        
Web Page (or Simply, “page”):                The “web page” (or simply, “page”) is a form of web content, and is the whole content that is to be displayed when the user designated a particular URI (Uniform Resource Identifier). In other words, it means the whole content that can be displayed by scrolling the image on the display. It is noted that a web page includes not only a page for browsing online but also a page for browsing offline. The web page for browsing offline includes, for example, pages transmitted via the Internet and cached by the browser, and pages saved in a “mht” format in places such as a local folder in a terminal device. The web page consists of various kinds of data such as a HTML document, an image file, and voice data.        
In accordance with the above definition, “content” encompasses “web content”, and “web content” encompasses “web page” and “page”.
The screen size of mobile terminals such as mobile phones is extremely small compared with, for example, desktop PCs. Therefore, when displaying, for example, a whole page in one screen in such a browser of a mobile phone, the displaying size of, for example, text and image included in the page becomes small, and its visibility becomes poor. Specially, when displaying pages created assuming, for example, desktop PCs, in a mobile terminal, the poor visibility becomes more serious.
As a function for improving the visibility of a page, mobile phone browsers may be implemented with a zoom function that displays the page in a magnified way. For example, a Japanese Patent Provisional Publication No. JP2005-316558A discloses a mobile phone capable of zooming in a desired portion in a page with a simple operation.